One perhaps putting Whistleblower Diaries entry about? (6)
I believe the answer is:
golfer
'one perhaps' is the definition.
I can't tell whether this definition defines the answer.
'whistleblower diaries entry about?' is the wordplay.
'whistleblower' becomes 'ref' (referee).
'diaries entry' becomes 'log' (I can't justify this - if you can you should believe this answer much more).
'about?' is a reversal indicator (I've seen 'about' mean this).
'ref'+'log'='reflog'
'reflog' in reverse letter order is 'GOLFER'.
'putting' is the link.
Can you help me to learn more?
(Other definitions for golfer that I've seen before include "McGinley or Harrington, say" , "Swinger on course" , "Driver, chipper and putter" , "Player with clubs and tees" , "Player on links" .)